Each summer, festival-goers converge on Kappabashi-Hondori (Kappabashi Street) in Tokyo’s Asakusa district for the Shitamachi Tanabata Matsuri, a festival traditionally held on July 7.

Ah, there it is. The first-magnitude star shining faintly on the dull celestial sphere must be Vega (Orihime in the Tanabata legend) in the Lyra constellation. I had given up on seeing it from the ...